Oven controlled crystal oscillators, frequently known as OCXO's, are well known in the industry. Generally, crystal resonators resonate at a frequency which varies with temperature. The magnitude of this variation is frequently controlled by using temperature compensation obtained with heat generating devices such as thermisters, resistors and infrared radiation. In U.S. Pat. 4,259,606 an infrared heater is employed to provide radiative heating of the resonator inside a vacuum and thus reduce the time needed to stabilize the operating frequency of the resonator. The resonator is supported by insulator mounts, which have thin conductors to make electrical contact with the operative surfaces of the resonator plate. The entire structure is then placed inside an evacuated enclosure with infrared radiation being applied through a window from outside the evacuated enclosure.
U.S. Pat. Nos. 5,500,628 and 5,438,219 describe a double sided oscillator package wherein a piezo element is mounted below a platform while other circuit components are located above the platform and wires are embedded inside the platform. Another OCXO is described in U.S. Pat. 5,180,942 which issued to Marvin et al. A ceramic package for a crystal oscillator is described in U.S. Pat. No. 4,627,533.
Although these prior art devices can be useful for portable applications, a problem arise from an inefficient heating of the resonator and the consequential reduction of the useful life of a battery charge.